3a-4b=0. 4a+3b=25 elimination method
Answers
Given :
• 3a - 4b = 0
• 4a + 3b = 25
To find :
• The value of a and b by using elimination method.
Solution :
→ 3a - 4b = 0 --------(1)
→ Transposing - 4b to the other side, on transposing it's negative sign will change into positive.
→ 3a = 4b
→ Transposing 3 to other side.
→ a = 4b/3 -------(2)
→ 4a + 3b = 25 -------(3)
→ Substituting (2) in this equation :-
→ 4(4b/3) + 3b = 25
→ 16b/3 + 3b = 25
→ (16b + 9b)/3 = 25
→ Transposing 3 to the other side.
→ 16b + 9b = 25 × 3
→ 25b = 75
→ Now, transpoing 25 to the right hand side :
→ b = 75 ÷ 25
→ Dividing both the digits by 5 :
→ b = 15 ÷ 5
→ Again dividing both the digits by 5 :
→ b = 3
→ The value of b = 3
Substitute the value of b in eqaution 1 :-
→ 3a - 4b = 0
→ 3a - 4(3) = 0
→ 3a - 12 = 0
→ 3a = 12
→ a = 12 ÷ 3
→ a = 4
→ The value of a = 4
Therefore, the value of a and b are 4 and 3 respectively.
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VERIFICATION :-
We can verify the value of a and b by putting them in equation (1) and if the resultant value will be equal to 0 as given. So, the values of a and b will be right.
→ 3a - 4b
→ 3(4) - 4(3)
→ 12 - 12
→ 0
• 3a - 4b = 0
Hence, verified.
3a-4b=0. 4a+3b=25 elimination method